1. Field of Invention
The present invention relates generally to the manual truing of spoked bicycle wheels and, more particularly, to the use of a wheel truing apparatus for hand truing of spoked wheels, and specifically to an apparatus for aligning wheel truing stands used for hand truing wire spoke bicycle wheels.
2. Discussion of Prior Art
Various apparatus and methods for assembling, tensioning, and truing (or aligning) spoked bicycle wheels are well known to those skilled in the art. A partial listing of patents which disclose pertinent methods and apparatus includes: U.S. Pat. No. 3,507,027, which issued on Apr. 21, 1970 to Eric Jaulmes; U.S. Pat. No. 3,789,475, which issued on Feb. 5, 1974 to Ian John Barwell; U.S. Pat. No. 3,841,379, which issued on Oct. 15, 1974 to Gary W. Kinney; U.S. Pat. No. 4,045,852, which issued on Sept. 6, 1977 to Andrew Gordon Winch; U.S. Pat. No. 4,418,738, which issued on Dec. 6, 1983 to Roland Kaufeldt; and U.S. Pat. No. 4,585,046, which issued on Apr. 29, 1986 to Ronald E. Buckley. All of the above listed patents disclose apparatus and/or methods for automated truing of spoked wheels, and are thus of limited relevance to the present invention, which relates to hand truing of spoked bicycle wheels.
Buckley discloses an apparatus comprising a tool capable of clamping the shank of each spoke nipple and rotating the nipple in the appropriate direction to increase or decrease the tension on the spoke, and means of determining the position of the rim portion associated with the respective spoke relative to a reference vertical plane and relative to a preferred reference circle. By increasing or decreasing the tension in each spoke in succession the rim is aligned in the vertical plane and in the preferred reference circle. Buckley thoroughly recites the components comprising a spoked bicycle wheel, the disposition of those components relative to one another, and the structure and requirements for disposition and alignment of the components so as to achieve the state of trueness for the wheel, all of which is well known to wheel-wrights and others skilled in the art of wheel building and truing. He further recites the method and procedure employed during manual truing of a spoked wheel, and briefly describes the configuration of a support apparatus, generally :referred to as a truing stand, that could be used for manually truing a spoked wheel. Buckley also describes the ideal or preferred alignment of a wheel rim with respect to its hub by reciting that the plane of the rim intersects the hub at a point generally midway between the hub's flanges. While this is true for a front wheel, the hub of which is generally symmetrical about the midpoint on the central axis of its axle, and thus about the midpoint between its flanges, it is not generally true for a rear wheel. The hub of a rear wheel is asymmetric about a vertical plane midway between the hub flanges, owing to the need to allow space and means for attachment of gear cogs on the right hand side of the bicycle. For both front and rear wheels the plane of the rim will ideally intersect the hub at a point midway between the hub's locknuts, which are associated with the anti-friction bearing mechanism disposed between the hub and its axle. The locknuts are the members of the wheel hub assembly that are in contact with the respective bicycle frame members in which the wheel is mounted. The locknuts thus determine the disposition of the wheel hub, and therefore the rim, with respect to the frame. The desired disposition of the rim is midway between the respective frame members of the bicycle. To achieve this desired disposition of the rim, the plane of the rim must be equidistant from the locknut at either end of the axle. This requirement for centering the rim between the locknuts, but not necessarily with respect to the hub flanges, is often referred to by practitioners of the art of wheel building as dishing, or the dish of a wheel.